1. Field of the Invention
The invention relates to apparatus for generating, recording and reproducing a video signal for display. The invention is particularly suitable for use in a self-contained video camera/recorder.
2. Discussion Relative to the Prior Art
Much research and development effort relating to video apparatus is presently being directed toward the realization of a hand-held, self-contained video camera/recorder resembling a conventional amateur film movie camera in size. Portable video camera/recorder combinations are presently commercially available, however, the hand-held cameras are physically separate from the larger video recorder/playback apparatus and electrically connected thereto by an umbilical cord.
Video tape playback apparatus customarily reproduces the video signal from the tape at a standard frame rate. Thus, the minimum bandwidth requirements for a tape recorder/player have conventionally been determined by the bandwidth of a standard video signal, e.g. up to approximately 10 MHz for a standard FM modulated color video signal. The relatively high bandwidth requirement for a video tape recorder/player militates against the miniaturization of the tape recorder apparatus required for packaging the recorder in a self-contained video camera/recorder of a size resembling a conventional movie film camera.
As is well known, each frame of a standard television signal comprises two interlaced fields so that, when viewed in sequence, the perceived effect is a picture having greater vertical resolution than either of the two fields viewed independently. In a procedure called "skip field recording", it is known to record only one field per frame, and upon playback to reproduce each recorded field twice in succession, thereby increasing the storage capacity of magnetic tape by a factor of 2. (See U.S. Pat. No. 3,391,248.) The resulting sacrifice in the vertical resolution of the reproduced picture is an acceptable trade-off in home video recording. Although the playing time may be increased, or conversely, the tape supply reduced, by this method, the bandwidth requirement of the video tape recorder/player remains as high as that of a conventional video recorder. Thus, although the size of the tape supply may be reduced by employing this procedure (skip field), miniaturization of the remaining components of the tape recorder is hindered by the relatively high bandwidth requirement.